CANADIAN COURT OVERTURNS LIPITOR PATENT

The invalidation of a key patent held by Pfizer could open the door to the manufacturing and marketing of atorvastatin tablets, a generic version of Pfizer's blockbuster cholesterol-lowering drug, Lipitor. The court upheld the validity of a second ingredient patent, which expires May 7.

In a decision handed down Jan. 26, the Federal Court of Canada upheld assertions made by Ranbaxy Laboratories that the '586 patent covering the calcium salt of atorvastatin, the active ingredient in Lipitor, is invalid. The court invalidated the patent because it said the language in the patent claims did not correctly and fully describe the invention.

The court denied an application submitted by Pfizer asking that the minister of health not issue a notice of compliance to Ranbaxy regarding generic atorvastatin. A notice of compliance must be granted before Ranbaxy is permitted to market its generic version of the drug in Canada.

The ruling clears a legal hurdle and "moves Ranbaxy closer to launching generic Lipitor," company spokesman Charles Capriello said. However, bringing the product to market still depends on obtaining marketing approval from Canadian authorities, he said.

Pfizer plans to file an expedited appeal in response to the ruling, spokesman Bryant Haskins said. "We are obviously calling into question the decision to deny our request to block their application [to market generic Lipitor]," Haskins said. An expedited ruling, depending on whether the court grants the request, would result in a decision sooner than the normal waiting period of six to eight months for an appeals court decision, Haskins said.